When viewing a scene from a distance, expected or unexpected obstructions may present themselves between the viewer and portions of the scene. A common example is a teacher present in front of a blackboard in a classroom or lecture hall obstructing some students from viewing the entire blackboard and its contents. An obvious consequence is that some viewers are at least temporarily unable to see beyond the obstruction and may miss important occurrences or content presented in the scene, such as information on the blackboard or visual elements of a slideshow.